An American author of homosexual-themed works, he is particularly known for such novels as The Strumpet Wind (1947) and The Demon at Noon (1954). His later works include Perfect Freedom (1982) and The Good Life (1997).
He studied French literature at Princeton University and subsequently acted in several Broadway plays.
He was one of the first people to write about homosexual themes for a large audience.
During his years as a Broadway actor, Merrick had a relationship with Moss Hart.
He and Wayne Rogers both studied at Princeton.